Zeroizing means for totalizing apparatus



Dec. 9, 1941. A. BINNS ZEROIZING MEANS FOR TOTALIZING APPARATUS FiledSept. 3, 1938 2 Sheets-Sheet l Dec. 9, 1941. A. BINNS ZEROIZING MEANSFOR TOTALIZING APPARATUS Filed Sept. 3, 1938 2 Sheets-Sheet 2 Ma$4bmaPatented Dec. 9, 1941 ZEROIZING MEANS FOR TOTALIZING APPARATUS ArthurBinns, Birmingham, England, assignor to W. & T. Avery Limited,Birmingham, England Application September 3, 1938, Serial No. 228,443 InGreat Britain September 8, 1937 1 Claim.

This invention has reference to improvements relating to zeroizing meansfor totalizing apparatus and is concerned particularly with zeroizingmeans for totalizing apparatus used in conjunction with indicatingmechanism of the kind described and claimed in the specification of mypending patent application No. 104,249, dated October 6-, 1936, nowPatent No. 2,173,575, issued September 19, 1939.

In order that the present invention may be the better understood itshould be recalled that in the indicating mechanism described in myaforesaid patent specification a secondary pointer is coupledmagnetically to the indicating pointer of an automatic indicatingmechanism so as to move with the indicating pointer during the movementthereof to the indicating poition and that the said secondary pointer isalso associated with an electro-magnetic clutch which is utilized toeffect simultaneously the breaking of the magnetic connection betweenthe secondary pointer and the indicating pointer and the clutching ofthe said secondary pointer to an electric motor which. is simultaneouslybrought into operation and caused to efiect the actuation of atotalizing apparatus, the electric motor remaining in operation until ithas effected the return of the secondary pointer to the initial positionand so actuated the totalizing apparatus to an extent governed by theposition to which the secondary pointer has been moved during itsassociation with the indicating pointer thus effecting a totalizing ofthe load, and that the bringing into operation of the el'ectro-magneticclutch is determined either by a switch which comes into operationautomatically to complete the circuit after a predetermined period oftime has elapsed subsequent to the commencement of the indicatingoperation, or by the completion of a circuit by the arbitrarymanipulation of a manually operable switch.

It is experienced in practice that it is required under some conditionsof working to provide for the zeroizing of the totalizing apparatus atthe will of the operator, and the present invention has for its objectthe provision of an improved means which enables zeroizing of thetotalizing apparatus to be efiected when desired, but which ensures thatonce a zeroizing operation has been initiated the zeroizing operationmust be completed before the indicating mechanism can again beeffectively employed.

The invention consists of a zeroizing means for totalizing apparatusemployed in conjunction with indicating mechanism of the kind hereinreferred to, characterized in that the zeroizing means is associatedwith an electric switch mechanism which is embodied in the circuit whichcontrols the operation of the electromagnetic clutch for disconnectingthe secondary pointer from the indicating pointer of the aforesaidindicating mechanism, so that on the actuation of the said zeroizingmeans the circuit through th control switch is maintained broken untilthe said means has been actuated. to an extent which ensures that acomplete zeroizing operation has been performed.

The invention further resides in the details of construction of thezeroizing mechanism for totalizing apparatus to be describedhereinafter.

This invention will now be described with reference to the accompanyingdrawings which illustrate a preferred construction and arrangement of azeroizing means for a weight totalizing apparatus incorporated with aWeighing scale having an indicating mechanism constructed, arranged andoperated as described and illustrated in the aforesaid Patent No.2,173,575.

In the drawings Figure 1 is a frontv elevation of the totalizingzeroizing mechanism associated with a switch which controls the circuitthrough the weight-indicating mechanism, this figure illustrating indotted lines alternative positions of certain parts of the mechanism.

Figure 2 is a side elevation of the mechanism seen in Figure 1.

Similar reference numerals indicate similar parts in the two views.

The totalizing apparatus which is of known kind is illustrated by thedotted rectangle designated 3 and this totalizing apparatus is zeroizedby the movement of a resetting shaft 4 which has fixed to a protrudingend thereof a crank arm 5 which makes contact with a roller 6 carried atthe one end of one arm of a lever l which is fulcrumed on the pin 8 inthe bracket 9 bolted to the housing 19 containing the weight-indicati'ngmechanism. The other end of the other arm of the lever 'I- is forked at7 and bears on the upper surface of a loosely mounted flanged bush Hwhich is slidable on the rod I2 and is maintained in contact with thelower face of the forked end of the lever l by means of a coiledcompression spring l3 surrounding part of the rod H. The rod 52 adjacentits upper end passes through the housing it which at this point isprovided with a pair of nuts m which are welded to the housing onopposite sides thereof, and which constitute bearings or guides for thispart.

of the rod. The lower part of the rod I2 is slidably mounted within thehorizontal limb I I of a bracket I4 secured to the housing I0. Pinned tothe rod I2 is a collar I5 which serves as an abutment for the upper faceof the flanged bush II and this collar also constitutes a stop toprevent the rod I2 from being wholly withdrawn from its mounting.

Fixed to a screwed section I2 of the rod I2 is a U-shaped bracket I6which can'be adjusted on the screw-thread by means of the lock nutsv I Ithe upper of this pair of nuts also constituting an abutment for thelower end of the coiled compression spring I3. One of the vertical limbsof the bracket I6 carries a laterally projecting pawl I8 which isadapted to co-operate with a plurality of ratchet teeth I9 formed on oneedge of a plate I9 which is pinned to the upper end of an upstanding armfulcrumed at its lower end on a spindle 2| which is carried by a block22 secured to the horizontal arm [4 of the bracket I4, the said arm 20being provided with a laterally projecting pin 26* which is disposedbetween a pair of leaf springs 23 secured to the block 22 which locationof the pin 2i] between the pair of leaf springs 23 serves to maintainthe arm 20 in the vertical position or to restore the arm to thevertical following any disturbance or displacement as will behereinafter described. The lower end of the rod I2 bears on aninsulating plate 24 which is connected to a metallic blade spring 25which carries one of the contact points 26 of the pair of contacts whichconstitute a switch in the circuit through the indicating mechanismreferred to in the prior specification.

The upper nd of the rod I2 projects through the housing I0 and isprovided with a knob ,I2 to facilitate manipulation.

The switch mechanism incorporating the insulating plate 24, the bladespring 25, and the contact points 26 is adjustably mounted on a bracket21 which in turn is secured to the housing, adjustment being obtained bymeans of the set screw 28 which determines the position of the switchcarrier plate 29 relative to the lower end of the rod I 2.

The number of ratchet teeth I9 is selected so that there is at least oneextra tooth beyond the maximum degree of travel which is required to begiven to the rod I2 in order to efiect a complete zeroizing motionthrough the lever I of the crank arm 5 associated with the spindle 4 ofthe totalizing apparatus 3.

The operation of the mechanism is as follows:

Normally the coiled spring I3 maintains the rod I2 in its lowermostposition, that is the position seen in full lines in the drawings inwhich position the lower end of the rod I2 makes con-- tact with theinsulating plate 24 and maintains the contact points 26 in the closedposition. When it is desired to effect a zeroizing of the totalizingapparatus the knob I2b is pulled upwardly or outwardly and through therod I2 and the associated flanged bush II raises the forked end of thelever I to the position seen in dotted lines in Figure 1, rocking thelever I so that the roller 6 on the one arm thereof rocks the crank arm5 and the spindle 4 until this arm 5 occupies the position seen indotted lines in Figure 1, which angle of motion imparts the necessarymovement to the spindle 4 to zeroize the totalizing apparatus in knownmanner. This upward motion of the rod I2 draws the pawl I8 over theratchet teeth I9, which motion is permitted by the pivotal mounting ofthe arm 20. When the pawl has passed over the whole of the ratchet teethIs to the position seen in dotted lines in Figure l, the rod I2 canautomatically return to its initial switch-closing position by the pawlpassing down the smooth edge of the ratchet plate I9, which action iseffected by the coiled compression spring I3 upon release of the knob I2As the spindle 4 and crank arm 5 are spring-loaded in known manner thearm 5 in turn through its contact with the roller 6 returns the lever Ito its normal position seen in full lines in the drawings, so that theforked end of the lever I maintains contact with the upper or outer faceof the flanged bush II. The lifting of the rod I2 permits of thebreaking of the contact points 26 owing to the resilience of the bladespring 25 which carries the upper of the pair of points, this break isindicated in dotted lines in Figure l, and it will be appreciated thatwhile this switch mechanism is in the open position no current can passthrough the circuit which operates the weight totalizing mechanismdescribed in the aforesaid specification, the contact points being againclosed or re-set when the rod I2 is returned to its normal position bythe action of the coiled compression spring I3.

In order to permit of the full stroke of the rod I2 so that the pawl I8can clear the ratchet teeth I9a irrespective of the angle of motionrequired by the lever I to eifect the determined rotation of the spindle4 through the crank arm 5, there is permitted what may be termed afurther upward motion of the rodIZ as determined by the collar I5, inthat the rod I2 can freely pass through the flanged bush II and thisbush is restrained from further upward motion by the lever I.

1 It will be appreciated that in order to permit the pawl I8 to properlytraverse over the range of all the ratchet teeth It? and down the plainedge of the ratchet plate, that a rocking motion has to be permitted tothe arm 29 about its pivot 2| and that the arm 29 will automatically becentralized or returned to its normal vertical position owing to thelocation of the laterally projecting pin 23 between the pair of bladesprings 23.

It will also be appreciated that if the pawl I8 is not traversed thecomplete distance to permit of its return to the normal position, thatis, the pawl is held by any one of the ratchet teeth I9 then the rod I2cannot be returned by the spring I3 to the position at which it willre-make the switch mechanism incorporating the contact points 26, andthat in consequence no operation of the weight-indicating mechanism cantake place until the complete zeroizing of the totalizing apparatus hasbeen effected.

What I claim is:

In an apparatus for displacement to zeroize a register, and formaintaining a switch open to render the register inoperative, whiledisplaced, in combination, a support, a rod mounted for limited slidablemanual displacement relative to said support, a collar slidable on saidrod, an

operating member biased toward said collar, having a limited range ofdisplacement, a spring surrounding said rod and urging said collartoward said operating member, which spring is capable of overcoming thebias of said operating member, a stop fixed to said rod to limit thedisplacement of said collar along said rod by said spring, the normalposition of said operating member being determinedby the normal positionof said rod,

and the limit of displacement of said rod being in excess of the limitof displacement of said operating member, said operating member, afterbeing displaced to the limit of its displacement, holding said collarstationary relative to said support and thereby compressing said springwhile said rod is displaced beyond the limit of displacement of saidoperating member, to permit such excess displacement of said rod, and alocking device for preventing return of said rod to normal positionuntil it has been displaced beyond the limit of displacement of saidoperating member.

ARTHUR BINNS.

